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1 - How exactly does does a Shellac finish applied by brush compare to the French Polish method? I won't to know if brush method looks close to or very different to French Polish method.
2 - Can you cut and Polish by hand or machine to a high mirror sharp finish? How did they do it back in the Victorian era? I read heat & pressure can melt Shellac, so wanted to ask.
thanks
The two finishes that you mention are very different. French Polishing is the process of filling up all the open grain in the timber with polish and pumice so that the surface is perfectly flat and you end up with a finish that is almost 3d in appearance. This cannot be achieved by using a brush, it can only be achieved using a polishing rubber. Brushed on shellac will not give the same result. The result is acceptable but nothing like French Polish. Shellac does not like heat.
Using a polishing rubber to apply shellac has been used for many many years and it takes quite a while to learn how to do it properly.
Both methods do give a good result but they are very different.
Regards
Router
Hi T,
I have had great results by flattening the surface grain with a bolster, applying shellac as a sanding sealer and then using EEE wax on a a low speed RAS with a non grit sanding pad (start with a 320 and run it on a steel plate until all signs of grit are gone before using it), and finish with MiniWax cabinet paste buffed with lambskin pads.
I only use a brush for those pars which the rubber cant reach
Rob
Thanks, why can't brush give a 3d look? shouldn't it still fill up grain?. Does the FP look 3d if it's buffed to a matte? Does brush have Chatoyancy?Quote:
Originally Posted by router
Anyway some other Questions I have with brush:
Does sanding between coats give any real benefit?
Do you use any cleaner in between coats or just wipe off dust with a rag?
If you can .. Get hold of Ubeauts French polishing handbook. It gives a great insight into working with shellac.
IMHO laying shellac on with a brush just doesn't get the surface flat ... And I mean flat like glass. A brush is quite fine to build up a base with, but I expect that for all but the most experienced, striving for that piano top finish is a bridge too far with a brush alone.
I recently tried my hand at something vaguely resembling French polishing on some overhead cupboards in my study and then spraying hardened shellac on the desk.
In both situations I learned a hell of a lot,
and Neil's book was a great reference.
To start with, surface prep is absolutely critical. Any imperfections, dents, machine marks, tool marks etc. that might be barely perceptible on raw timber will look like the surface of the moon under a well applied shellac finish. Neil recommends (from memory) sanding to at least 1200 grit working up through the grades. Grain filling is also recommended. This can be done with shellac ... But it just takes longer to completely choke the grain. I used timber mate ... Although there are some that believe the finish is not as deep with grain fillers. I never did try a comparison.
Neil also recommends the use of a tack cloth to clean the surface, as any dust will mar the finish. I used micro fibre cloths and was happy with the results.
In answer to sanding between coats, the answer is yes, it's perfectly acceptable. In my case, following surface prep, the more body I put on, the finer the sanding became. Generally speaking, after laying down a base, I sanded with 800 wet and dry on a cork block (with a few drops of detergent in the water). The key points here are to
1. Avoid sanding through the shellac back to bare timber and
2. Flatten the surface.
I found that as the body built up and the finish gave more depth, "hollows" became visible in the surface. I don't mean grain voids, but very slight hollows that reflected the light differently. I think it's the progressively finer sanding that helps to knock these back.
Maybe the surface waves (peaks and hollows) were put there by me during the polishing process, maybe they are just inherent in the timber, but I am talking about surface variations that might possibly be measured in microns.
Anyways, at the next step i sanded with 1200 grit wet and dry. Again, the hollows become visible as glossy sections that the paper hasn't hit yet (compared to the matte sections where the paper has cut the surface). Again, keep sanding until all the glossy sections are gone.
After I was satisfied, I put on another coat, then sanded again, and then the magic ... EEE ultrashine with a swansdown mop ... And hey presto ... A satin finish with a silky feel (not plasticky).
Hope that helps a little ...
What a brush does and a rubber does is two different things, I do remember a long time ago wondering why a brush or spray gun could not do what a rubber did. And I tried a few times to cheat my way around it . There are ways to make it happen faster Ive used, but the basics of what a rubber does has to be stuck to and understood.
By brushing or spraying you have to lay a lot on to try and flood fill the grain , the shellac when dry does not cut right back that easy either to the nice flat thin finish that french polishing is known for .
Application with a rubber on suitable timbers can build and fill the grain while not just laying more on top of the top of the flat the same time .
Working the shellac with a rubber pushes the shellac sideways and fills low open grain . Three good goes of circles and 8s 9 (Good body's ) on a reasonable timber with a fine grain , not a huge open one . with a decent cut back in between can have the low spots come up to the same level as the flat top and give the thin fine finish that the french polishing method is known for. Fine finish, thats if you know the difference between the bodying sessions and the finishing and can get good at that as well .
Brushing or spraying cant do the grain filling like that.
Knowing how to use the thickness of the shellac mix is one important thing when bodying . By knowing that and brushing a coat on then using the polishing rubber at exactly the right time you can body faster . There is a lot more to it but the mix the timing and knowing when to stop is what I think its all about . Once you know that and play in that direction you will start to see the results . But you have to remember that you have to give it three goes, three body's with decent cutbacks . You don't see any result after the first go, and with experience you may just be able to spot whats going on after the second body , its the third body where it really shows up whats going on when it comes to filling the grain.
Rob
....or maybe go to 600 wet and dry....maybe 800 after 320 grit...have had great results...
Thanks for your help. I have tried the EEE ultrashine with a swansdown mop with other finishes, to me that seemed like a preliminary stage, you still had to hit with a finer polish to get the faint buff marks out.Quote:
Originally Posted by Glenn.Visca
One other question hopefully you or someone else might be able to answer is, whether brush or FP is it usually acceptable to stain the wood? I ask as shellac comes in colours which can vary on angles & has depth so staining the wood might affect or minimize the look.
I didn't notice any buff marks on my work ... But then my eyes ain't that great either.
According to Neil, as you work the EEE, the Tripoli powder continues to break down into finer and finer particles. He also says to clean the surface with a rag to remove as much grit as possible. And ... It's quoted as a finisher of finishes.
But anyways...
During my study build, I had the pleasure of speaking with the owner of Shines ( who are a wholesale shellac flake provider).
His comments to me ( which I can't say I have tried to any great extent yet) is that the colour of the shellac will highlight the same tones in the timber. So (and others correct me please !) for blonde timbers use a lighter shade, for red timber a ruby shellac, and for brown timber a garnet.
I don't think one should consider shellac as a stain. Granted ... It will "tone" the timber ... But I doubt it will have any great effect as a stain.
I'm late to this party, but here goes:
Staining before polishing is standard practice if the timber colour does not match the colour that you are seeking. A shellac finish is suitable for indoor use, so the best stains are spirit stains and water stains. Do not use oil stains as they are muddy in appearance. Normally you would stain the raw timber before applying shellac. I have added spirit stain to shellac when I need some more colour (in an antique restoration) but that is not the ideal technique. These days I use Wattyl stains and they come in various supposed timber colours or in some simple colours that you can combine. Make sure you practice on some scrap timber of the same kind first.
To reiterate what others have said above: polishing with a rubber gets you a lovely transparent finish; polishing with a brush, even a super special, super fine hair brush like one of the Leonhardy brand brushes available from gilding companies (search on the forums I have posted here on the Australian supplier - not connected to me), will get you a good finish but not the equal of a rubber finish. Whether you use a brush or a rubber it is essential to cut back between every few coats to get a decent finish.
Now, maybe I have been doing this too long, but I do not find polishing with a rubber to be difficult. In fact, I would say that it is easier than using a brush (except for deep carving and deep turnings of course), and that a decent rubber can be made from a bit of old sheet and some cotton wool, so give it a go, you will be glad that you did.
Thanks, this info helped. Looks like alot of variations with color are possible.Quote:
Originally Posted by Glenn.Visca
Thanks, alot of help in this post. I have watched some vids & it looks easy.Quote:
Originally Posted by Xanthorrhoeas
Not sure but it looks like the rubber method gives an almost perfect mirror surface that is good enough for final result. Something a fine brush could never do from my experience.
If one want's to lite sand, buff & polish the FP to a smoother more mirror flat surface, I assume the amount of sessions of FP would have to be MUCH more to produce a more thicker film so you want rub through it.
The great thing about a rubber finish is that you choose the gloss level that you want. My darling wife does not like high gloss in anything I make for her, so unless I sneak some in, that is not the norm in my finishes. However, I always use a rubber even when I stop at a satin level finish (although I wax over it so it does improve in transparency from satin).
The diffeence between a good satin level French Polish and a high gloss finish is actually often only a few coats. It does depend on the shellac that you use.